Total neutron cross section of scandium from 0.005 to 22 keV

The size of the neutron cross-section minimum in 45Sc is important in the optimum design of filters for the production of 2-keV neutron beams. The scandium total cross section was measured from 5 eV to 22 keV, an energy region in which high-resolution and high-precision cross-section data did not previously exist. The samples used are in metallic form having thicknesses ranging from 0.2 to 30.5 cm. The cross section at the (2.05 +- 0.02)-keV minimum is (0.71 +- 0.03) b, in sharp contrast to the previously accepted value, 0.085 b. The size of the cross section indicates that an optimum scandium filter would be shorter than what is conventionally used. An R-function shape fit with constraints from the known thermal cross sections showed that J = 3 scattering dominates at thermal energy, in contradiction to a previous result obtained by polarization techniques. The conclusion is supported by 45Sc(n,γ) spectra, and the transmission measurements using polarized neutrons and targets. Scandium level parameters were extracted for each observed resonance up to 22 keV. S-wave strength functions and average level spacings were also evaluated for both spin states. 3 figures, 3 tables